Inherently Eu /Eu Codoped Sc O Nanoparticles as High-Performance Nanothermometers.

Luminescent nanothermometers have shown competitive superiority for contactless and noninvasive temperature probing especially at the nanoscale. Herein, we report the inherently Eu /Eu codoped Sc O nanoparticles synthesized via a one-step and controllable thermolysis reaction where Eu is in-situ reduced to Eu by oleylamine. The stable luminescence emission of Eu as internal standard and the sensitive response of Eu emission to temperature as probe comprise a perfect ratiometric nanothermometer with wide-range temperature probing (77-267 K), high repeatability (>99.94%), and high relative sensitivity (3.06% K at 267 K). The in situ reduction of Eu to Eu ensures both uniform distribution in the crystal lattice and simultaneous response upon light excitation of Eu /Eu . To widen this concept, Tb is codoped as additional internal reference for tunable temperature probing range.